Indonesia: Increased volcanic activity ongoing at Ruang Volcano in North Sulawesi Province as of April 20 /update 3

Flight disruptions and evacuations are ongoing as of April 20 following increased volcanic activity at Ruang Volcano in North Sulawesi Province. Authorities have raised the alert level to level 4 (the highest level on a four-tier scale) and widened the exclusion zone to 6 km (4 miles) around the volcano. Over 11,000 residents of Ruang and southwest Tagulandang islands have been ordered to evacuate to nearby islands; evacuation centers are located in the eastern part of Tagulandang and Manado. Authorities have also warned of possible tsunamis if parts of the volcano collapse into the sea. Disruptions to communications services have been reported on Ruang Island.

Sam Ratulangi International Airport (MDC) in Manado, North Sulawesi Province, was closed as a precaution April 18 due to volcanic ash detected at the airport; it remains unclear when normal operations will resume. In Malaysia, AirAsia (AK) canceled flights between Kuala Lumpur International Airport (KUL), Tawau Airport (TWU), and Kota Kinabalu International Airport (BKI) April 18 and 19, with some disruption likely ongoing April 20. Malaysia Airlines (MH), however, has resumed flights connecting Kuala Lumpur International Airport (KUL) with airports across Sabah and Sarawak as of April 20. Further disruptions are likely if eruptive activity continues and winds direct ash clouds toward nearby airports.

The volcano has erupted more than ten times since April 16, emitting ash clouds at least 2.5 km (1.5 miles) above the crater and lava flowing down its flanks; a magnitude-5.3 earthquake near North Maluku Province at 00:40 April 14 could have triggered the volcanic activity. The eruptions produced a volcanic ash plume that spread volcanic ash to nearby roads and villages. Additional eruptions could cause low-level seismic activity, ash clouds, pyroclastic flows, and landslides in the surrounding area. Road conditions could quickly deteriorate during periods of significant ashfall, and visibility could be reduced. Officials may close roads near the volcano depending on the presence of hazardous volcanic material. Fine particulate matter ejected from the volcano could pose a hazard to flights in the surrounding airspace.

Further volcanic activity may impact air quality in North Sulawesi Province and neighboring areas. Individuals in the region - especially those with underlying pulmonary conditions such as asthma, chronic obstructive pulmonary disease (COPD), or lung cancers - may experience difficulty breathing and could suffer from lower tolerance to physical exertion.